Electromagnetic field stimulator device for anatomic biophysical chondroprotection

Abstract

Electromagnetic field stimulator device in which a current generator device supplies a solenoid with current the waveform of which includes the repetition of a ramp having a certain slope. This current causes the generation of an electromagnetic field that induces on a control probe irradiated by the electromagnetic field, an induced voltage of markedly constant amplitude during the ramp-like linear growth period of the current. This electromagnetic field is used to preserve the integrity of articular cartilage subject to degeneration.

1. An electromagnetic field stimulator device for Anatomic Biophysical Chondroprotection, comprising:
 means of current generation for powering at least one solenoid to generate an electromagnetic field directed on a part of the human body including cartilaginous tissue, 
 wherein said means of current generation supplies said solenoid with current (i(t)) having a waveform that includes the repetition of a linear ramp with a certain slope; said current (i(t)) causing the generation of an electromagnetic field that induces on a control probe irradiated by said electromagnetic field, a voltage (Vin) of markedly constant amplitude during the ramp-like linear growth period of said current (i(t)). 
 
   
   
     2. A device according to  claim 1 , wherein said means of current generation include at least one table in which at least one function (f(t)) is stored that provides, for each value of a scanning signal in input (sc), an output value that expresses a target current intensity (Iout), the said function f(t) being a linear one and representing a ramp with a certain slope that supplies, for increasing values of said scanning signal in input (sc), linearly increasing values of said target current intensity (Iout). 
   
   
     3. A device according to  claim 2 , wherein said table includes a plurality of functions (f(t)) of different, selectable types. 
   
   
     4. A device according to  claim 2 , further comprising timer devices suitable for generating said scanning signal in input (sc). 
   
   
     5. A device according to  claim 2 , further comprising attenuator devices having their input communicating with the output of said table, said attenuator devices being suitable for reducing the value of said target current intensity (Iout) in function of a programmable parameter (IPK) to limit the maximum value of said current (i(t)) feeding said solenoid. 
   
   
     6. A device according to  claim 1 , further comprising a feedback system for continuous monitoring of said current (i(t)) present in said solenoid, and comparing a measured current value (Imis) with a reference value (Iout);
 wherein in cases of variances between said measured current and reference values, due to changes in impedance of said solenoid, said feedback system automatically adjusts the value of said current (i(t)) feeding said solenoid in order to maintain the waveform of said induced voltage (Vin) unaltered. 
 
   
   
     7. A device according to  claim 6 , wherein said feedback system includes:
 detector devices suitable for supplying said measured current value (Imis), and 
 subtraction devices suitable for generating an error signal in function of said measured current value (Imis) and of said reference value (Iout). 
 
   
   
     8. A device according to  claim 7 , wherein a generator circuit is provided that receives said error signal in input and generates an alternating analogue power signal (S(t)) having a fixed frequency and variable duty cycle in function of said error signal, said variable duty cycle being suitable for regulating the intensity of said current (i(t)). 
   
   
     9. A device according to  claim 8 , wherein said generator circuit includes a pulse width modulator. 
   
   
     10. A device according to  claim 8 , further comprising low-pass filter devices between the output of said generator circuit and said solenoid. 
   
   
     11. A device according to  claim 1 , wherein said solenoid is made from a plurality of sheets of a flexible material to be adapted to the shape of said portion of the human body. 
   
   
     12. A method for Anatomic Biophysical Chondroprotection, comprising the steps of:
 providing the current generating means of  claim 1 , 
 generating an electromagnetic field; and 
 applying the electromagnetic field to a portion of the human body including cartilaginous tissue, wherein said step of generating an electromagnetic field includes the step of: 
 powering a solenoid with current (i(t)) from said current generating means having a waveform that includes the repetition of a ramp with a certain slope, said current (i(t)) causing the generation of an electromagnetic field that induces on a control probe irradiated by said electromagnetic field, a voltage (Vin) of markedly constant amplitude during the period of ramp-like linear growth of said current (i(t)). 
 
   
   
     13. A method according to  claim 12 , wherein said current (i(t)) presents an intensity and said solenoid presents a configuration such that said electromagnetic field penetrates in depth into said portion of the human body until it permeates said portion of cartilage and a portion of subchondral bone associated with said portion of cartilage over their entire thickness and in their entire extension, to activate at intracellular level a process selected from at least one of:
 a process of articular inflammation control regarding both subchondral bone and the articular structures, 
 a process of articular inflammation control capable of acting in a specific manner on the adenosinic receptors A2A of the cell membrane of pro-inflammatory cells, neutrophils, doubling the number of bonds with adenosine, 
 a process of inhibiting the catabolic effect of inflammatory cytokines acting directly on the chondrocite and on the cartilaginous matrix, 
 a process of increasing the metabolic activity of chondrocites and the synthesis of proteoglycans, 
 a process of inhibiting degeneration of articular cartilage, preserving the integrity of the same articular cartilage, 
 a process of rapid healing of subchondral bone tissue, 
 a process of healing bone marrow edema regarding the subchondral bone of femoral condyles, and 
 a process of healing and integration of bone grafts after ligament reconstruction operations on the fibrous flexor sheaths of the knee. 
 
   
   
     14. A method according to  claim 12 , wherein said current presents an intensity and said solenoid presents a configuration such that said electromagnetic field penetrates in depth into said portion of the human body until it permeates said portion of cartilage and a portion of subchondral bone associated with said portion of cartilage over their entire thickness and in their entire extension, to activate, in the presence of an osteo-cartilaginous graft, a preservation process for the viability of said portion of cartilage and trigger an effect selected from at least one of:
 inhibition of reabsorption phenomena on the underlying bone, 
 rapid anchorage of graft, 
 good osteointegration of graft, and 
 inhibition of the formation of bone cysts. 
 
   
   
     15. A method according to  claim 12 , wherein said solenoid is made from a plurality of sheets of a flexible material to be adapted to the shape of said portion of the human body.